In an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), cells of different coverage sizes are deployed to improve cell coverage or to offload traffic. In an E-UTRAN network, small cells (e.g., pico cells, relay cells, or femto cells) are deployed with overlaid large cells (e.g., macro cells). A network including large cells and small cells is referred to as a heterogeneous wireless communication network or, for simplicity, as a heterogeneous network.
Macro cells and small cells may operate in different frequencies. For example, in a heterogeneous network consisting of macro cells and pico cells, the macro cells may operate on one frequency while the pico cells may operate on another frequency. Operating the macro cells and pico cells on different frequencies helps to reduce the interference among cells.